1. Field of the Invention
The invention relates to a method and device for machining holes or shapes of varying profile in a mechanical workpiece using an excimer laser. It is applicable in particular in aeronautical engineering to the piercing of cooling holes in the vanes and combustion chamber of a turbine engine.
2. Summary of the Prior Art
It is known to machine holes of varying profile using an electro-discharge machining (or EDM) technique. This technique has the major disadvantage of requiring the use of an electrode having a shape which is identical to the shape required for the hole that is to be made, this electrode itself having to be machined. Furthermore, this machining process is too slow.
The piercing of holes of varying profile using a laser beam and means for rotating the beam about the generatrix of a cone is also known, such as from French patent No. 2637524. The hole produced is funnel-shaped, but the dimensions of the conical part and the length of the cylindrical part downstream of the conical part are difficult to control in an industrial process.